Gastroparesis is a disorder of gastric function characterized by delay in gastric emptying, frequently associated with chronic nausea and vomiting, early satiety, postprandial fullness, abdominal pain, and malnutrition that may require nutritional support. Gastroparesis has a devastating impact on quality of life and predominantly affects younger women. In the past 5 years, the Gastroparesis Clinical Research Consortium (GpCRC) has made a series of important contributions (see below) to improve our understanding of this disorder and advancing the goals of patients, physicians and the NIH for management of gastroparesis. Yet, much remains to be learned about its etiology, natural history, treatment strategies, and clinical course, which is the rationale behind our response to the Continuation of the Gastroparesis Consortium RFA-DK-10-502. The biggest barrier to effective therapeutic approaches to gastroparesis is our lack of knowledge about either its pathogenesis or its pathophysiology. Further, the correlation between the major symptoms such as nausea, vomiting, pain, and current methods to measure change in gastric function (electrical, motor activity, meal emptying times) is poor at best. Finally, we do not understand the long-term outcomes of these patients and whether outcomes differ on the basis of etiology, symptom severity, and degree of emptying abnormalities. Consequently, our approach to these patients is erratic and treatment has been empirical and only partially effective, if at all, in relieving the major symptoms. The mission of the GpCRC is completely aligned with the recommendations of the National Commission on Digestive Diseases;5 specifically, Research Goal 2.6 relates to gastroparesis and states: Understand the noxious visceral signaling causing nausea and vomiting related to gastric neuro-electrical and/or motor dysfunction and the bi-directional brain-gut interactions. Gastroparesis provides an archetypal disease for investigative inquiry. Chronic vomiting, a debilitating and socially isolating digestive symptom, creates potentially life-threatening disruptions in fluid and electrolyte homeostasis and compromises nutritional status. Chronic nausea remains a significant hidden disability. Nausea and vomiting usually occur in tandem and overlay with other Gl symptoms as well as presenting in numerous digestive diseases. More effective treatments for nausea and vomiting would improve quality of life and physical functioning in a vast array of illnesses. A paucity of research exists for defining peripheral noxious signaling of nausea and vomiting related to primary Gl motor/sensory disturbances. The Specific Aims of this proposal are to: 1. Complete the current GpCRC registry; 2. To continue the GpCRC core lab, responsible for anatomic and related studies on tissue sample of patients with Gp syndromes; 3. Continue pharmacologic studies on patients with Gp syndromes; 4. Continue device studies for patients with the Gp syndromes; and 5. A new multicenter study, based on several GpCRC ancillary studies and other pilot data.